Information letters and advice notes
The Drinking Water Inspectorate uses Information letters and Advice notes to communicate with the water industry, local authorities and other relevant parties.
Information letters are used by DWI to communicate any changes in regulatory matters and Advice notes relate to changes in guidance or procedures.
They are automatically sent to named contacts but are available on request to anyone.
The list below includes only those letters that contain current information. Many older letters have been superseded. However, copies of such letters are available by contacting dwi.enquiries@defra.gov.uk
2024
REF | TITLE | Annex |
---|---|---|
03/2024 (Aug 2024) | INFORMATION LETTER | |
R31-01/2024 (Aug 24) | INFORMATION LETTER | N/A |
02/2024 (July 24) | INFORMATION LETTER The Water Industry (Suppliers’ Information) Direction 2024
| |
01/2024 (Revised) (Aug 24) | INFORMATION LETTER Annual Provision of Information on Consumer Contacts
| |
01/2024 (Feb 24) | ADVICE NOTE | N/A |
2023
REF | TITLE | Annex |
---|---|---|
03/2023 (Aug 23) | INFORMATION LETTER
| N/A |
02/2023 (Mar 23) | INFORMATION LETTER | N/A |
01/2023 (Feb 23) | INFORMATION LETTER |
Annex A – File Specification |
2022
REF | TITLE | Annex |
---|---|---|
05b/2022 Revised (Dec 22) | INFORMATION LETTER Guidance for water companies in Wales with respect to drought orders | N/A |
05a/2022 Revised (Dec 22) | INFORMATION LETTER Guidance for water companies in England with respect to drought orders | N/A |
04/2022 Revised (Dec 22) | INFORMATION LETTER
| Annex A – Provision of information to the Drinking Water Inspectorate in respect of section 10 of the Water Industry (Suppliers’ Information) Direction 2021 |
03/2022 (Jul 22) | INFORMATION LETTER Information Letter 03/2022 is revoked | N/A |
02/2022 (Mar 22) | INFORMATION LETTER | N/A |
01/2022 (Mar 22) | INFORMATION LETTER | |
01/2022 (Jan 22) | ADVICE NOTE | N/A |
2021
REF | TITLE | Annex |
---|---|---|
05/2021 (Oct 21) | INFORMATION LETTER Information Letter 05/2021 is revoked | N/A |
04/2021 (Sep 21) | INFORMATION LETTER Code of Practice on Technical Aspects of Fluoridation of Water Supplies 2021 (PDF 113KB) | Code of Practice on Technical Aspects of Fluoridation of Water Supplies 2021 (PDF 561KB) |
03/2021 (Aug 21) | INFORMATION LETTER Radioactivity Notices (exemptions for monitoring) under the Water Supply (Water | Annex A – Conditions and Requirements for Radioactivity Exemption Applications (PDF 111KB) |
02/2021 (Apr 21) | INFORMATION LETTER The Water Industry (Suppliers’ Information) Direction 2021 (PDF 113KB) | Information Direction 2021 (PDF 260KB) – supersedes the Water Industry (Suppliers’ Information) Direction 2020 |
01/2021 (Apr 21) | INFORMATION LETTER | Annex A – Guidance and Specification (PDF 167KB) Service reservoirs, contact tanks and final water tanks template (XLS 19KB) Treatment chemicals template (XLS 19KB) updated 12/10/23 |
2020
REF | TITLE | Annex |
---|---|---|
07/2020 (Nov 20) | INFORMATION LETTER The Water Industry (Suppliers’ Information) Direction 2020 (PDF 80KB) | Information Direction (PDF 104KB) |
06/2020 (Sept 20) | INFORMATION LETTER | N/A |
05/2020 (July 20) | INFORMATION LETTER Chloramination disinfection and associated risks of cyanide formation in treated water (PDF 106KB) | N/A |
04/2020 | INFORMATION LETTER Information Letter 04/2020 is revoked | N/A |
02/2020 | ADVICE NOTE Welsh version: At Aelodau Bwrdd a Chysylltiadau Bob Dydd Cwmnïau Dŵr a Charthffosiaeth a Chwmnïau Dŵr yng Nghymru a Lloegr (PDF 190KB) | N/A |
01/2020 | ADVICE NOTE | N/A |
03/2020 | INFORMATION LETTER Information Letter 03/2020 is revoked | N/A |
02/2020 | INFORMATION LETTER Information Letter 02/2020 is revoked | N/A |
01/2020 | INFORMATION LETTER Information Letter 01/2020 is revoked | N/A |
2019
REF | TITLE | Annex |
---|---|---|
03/2019 (Jun 19) | INFORMATION LETTER The Water Industry (Suppliers’ Information) Direction 2019 (PDF 248KB) | The Information Direction 2019 (PDF 92KB) Annex A (PDF 54KB) Updated GIS Specification Annex B (PDF 133KB) Revised file specification for compliance data returns Annex C (Excel 172KB) Updated Parameter list (updated March 2024) |
02/2019 (Apr 19) | INFORMATION LETTER | Annex A Guidance and Specification – Regulation 28 Reports (PDF 203KB) |
01/2019 (Apr 19) | INFORMATION LETTER Drinking Water Quality Legislation (PDF 127KB) | N/A |
2018
REF | TITLE | Annex |
---|---|---|
03/2018 (Dec 18) | INFORMATION LETTER METALDEHYDE – Recent developments and actions required (PDF 127KB) | N/A |
02/2018 (Aug 18) | INFORMATION LETTER | Annex A – Guidance and Data Specification – Monitoring Variation Applications (PDF 173KB) (Version 2 updated Nov19) Annex B – Guidance and Specification – Regulation 28 Reports Updated in annex A of IL 02/2019 (PDF 203KB) |
01/2018 (Jul 18) | INFORMATION LETTER Drinking Water Quality Legislation (PDF 87KB) | N/A |
2017
REF | TITLE | Annex |
---|---|---|
04/2017 (Dec 17) | INFORMATION LETTER Regulatory Sampling Programme (PDF 63KB) | N/A |
03/2017 (Sept 17) | INFORMATION LETTER Update to guidance documents including a guidance note on long term planning for drinking water quality (PDF 119KB) | N/A |
02/2017 | INFORMATION LETTER Further guidance on Chromium in drinking water (PDF 122KB) | N/A |
2016
REF | TITLE | Annex |
---|---|---|
04/2016 | New drinking water quality legislation (2016) (PDF 152KB) | N/A |
02/2016 | Legislative changes relating to the DWI cost recovery scheme (PDF 61KB) | N/A |
2015
REF | TITLE | Annex |
---|---|---|
02/2015 | Legal Instruments – Processes for reporting on, agreeing changes to and closure/revocation (PDF 113KB) | 1 – Undertaking progress (Word 45KB) |
2014
REF | TITLE | Annex |
---|---|---|
02/2014 | Regulation 28 reporting requirements (PDF 110KB) | A – General requirements |
01/2014 | Metaldehyde and other pesticides (PDF 134KB) | N/A |
2013
REF | TITLE | Annex |
---|---|---|
05/2013 | Drinking water analysis and the regulatory requirements (PDF 95KB) | N/A |
04/2013 | 1 – Return template (excel 438KB) |
2012
REF | TITLE | Annex |
---|---|---|
07/2012 | Publication of further research on nitrosamines in water treatment coagulants and drinking water (PDF 102KB) | N/A |
06/2012 | Regulation 15 compliance arrangements (PDF 180KB) | N/A |
02/2012 | Arrangements for demonstrating that reporting of analytical results meet regulatory requirements (PDF 70KB) | N/A |
2011
REF | TITLE | Annex |
---|---|---|
05/2011 | Production, delivery, receipt and control of water treatment chemicals (PDF 101KB) | N/A |
01/2011 | Amendment to The Water Supply (Water Quality) Regulations 2010 (Wales) (PDF 92KB) | N/A |
2010
REF | TITLE | Annex |
---|---|---|
10/2010 | Guidance on using contractors to deliver Local Authority duties under the Private Water Supplies Regulations (PDF 113KB) | N/A |
2009
REF | TITLE | Annex |
---|---|---|
4/2009 | Submission of raw water monitoring data to the Drinking Water Inspectorate (PDF 138KB) | A – Table format for reporting raw water (PDF 34KB) |
2007
REF | TITLE | Annex |
---|---|---|
08/2007 | Guidance on implementation of Regulation 16(2)(d)(i) (PDF 130KB) |
2005
REF | TITLE | Annex |
---|---|---|
12/2005 | A – Guidance on sample and sample extract stability trials (PDF 169KB) | |
03/2005 | Guidance on the calibration and analytical quality control for residual chlorine measurements (PDF 76KB) | Guidance (PDF 169KB) |
2004
REF | TITLE | Annex |
---|---|---|
11/2004 | Information requirements following notification of an exceedence of a regulatory standard (PDF 80KB) | A – Pro forma (PDF 70KB) |
05/2004 | Commencement of Part 3 Provisions of Water Act 2003 (PDF 82KB) | N/A |
2003
REF | TITLE | Annex |
---|---|---|
12/2003 | Procedures for the Delivery of Water Treatment Chemicals (PDF 82KB) | N/A |
2001
REF | TITLE | Annex |
---|---|---|
02/2001 | Water Supply (Water Quality) Regulations 1989: Guidelines for Calibration in Laboratories (PDF 251KB) | N/A |